1. Field of the Invention
This invention relates to apparatus for preventing accumulation of debris such as clay, dirt or stones in the flighting of an elongated earth auger which could fall on adjacent workmen or equipment as the auger is being removed from a bore hole while continuing to rotate.
Although the cleaning device of this invention may be used on various types of earth augers, it has particular utility for preventing clay, dirt or rocks from accumulating in the flighting of earth augers employed to dig bore holes which ultimately receive concrete to form a pier. Earth augers of this type generally have a central hollow shaft for delivery of cementious material as the auger is withdrawn from the bore hole. Problems have been encountered in instances where clay, dirt, stones or mixtures of this debris collect in the auger flighting so that as the auger is withdrawn, the debris may becomes dislodged from the auger flights and fall onto adjacent workmen or equipment. Continued rotation of the auger as it is being withdrawn from the bore hole exacerbates the tendency of material which has accumulated in the auger flighting to be flung therefrom from the auger onto personnel around the auger, or onto adjacent equipment, tending in many instances to damage such equipment.
2. Description of the Prior Art
A typical auger for drilling bore holes to be filled with cementious material to present a pier, or for other purposes, is illustrated in my prior U.S. Pat. No. 4,966,498. As schematically depicted in that patent, an auger 22 is suspended from a upright, box-like support frame which rests on the ground and extends upwardly from the area in which a bore hole is to be drilled. A crane or other similar unit may be employed to maintain the upright frame in its essentially vertical disposition.
As the auger is rotated about its longitudinal axis in a direction to cause the auger to dig a cylindrical bore hole in the ground, clay or dirt elevated to the surface of the ground by the auger flighting is deposited in the annular area surrounding the auger. When a bore hole of required depth has been formed, the auger is lifted from the hole while rotation thereof is continued in order to provide assurance that the bore hole will retain essentially its desired cylindrical shape.
Rotation of the auger during withdrawal increases the likelihood though that any clay, dirt, rock or mixtures thereof that has accumulated in the auger flighting will be thrown from the auger by centrifugal force, thereby endangering adjacent workmen or equipment. The problem is especially acute in connection with heavy clays which can substantially fill the spiral space defined by the auger flights, and become dislodged from the auger after a section thereof completely or partially filled with clay clears ground level as the auger is retracted from the bore hole.
In view of the fact that bore holes formed in the ground to receive concrete which presents piers or the like are usually relatively deep, it is the usual practice to dig such holes with an auger that is made up a number of connected, end-to-end auger sections. This is dictated at least in part by the fact that the auger can be handled and transported only when it is constructed of individual, end-to-end sections, which upon dismantling are of a size that can be loaded on trucks for over the road transfer from one job site to another.
It is apparent therefor, that any device to be used for the purpose of cleaning out clay, dirt or stones that tends to accumulate in the flighting of an earth auger should meet at least two criteria. First, the cleaning device must be capable of accommodating cylindrical connectors used to join adjacent auger sections in end-to-end relationship. Second, the cleaning device must be deflectable when a cleaning element thereof encounters debris wedged in the auger flighting to a degree that upon engagement of a cleaning element of the device with such debris, damage to the cleaning device would occur.